The P2063: Reductant/Regeneration Supply Control Circuit Low refers to a fault where the supply control circuit for the reductant (DEF) or regeneration system is experiencing low voltage. This low voltage condition can affect the system’s ability to properly control the supply of reductant or regeneration fluid, leading to improper emissions control. The issue may stem from faulty components, wiring problems, or connector issues.
P2063 – Quick Overview
| Code | Information |
|---|---|
| Meaning | P2063: Reductant/Regeneration Supply Control Circuit Low |
| Is it serious? | Yes, this can prevent proper functioning of the reductant or regeneration system, leading to increased emissions. |
| Possible causes | – Low voltage in the supply control circuit – Faulty components or wiring – Connector issues |
| How to diagnose? | – Measure voltage in the supply control circuit – Test the components – Check wiring and connectors |
P2063 Meaning
The P2063 code indicates that the supply control circuit, which is responsible for managing the delivery of reductant (DEF) or regeneration fluid into the exhaust system, is experiencing low voltage. This low voltage could lead to improper dosing of the reductant or regeneration fluid, resulting in poor emissions control and potentially triggering warning lights. This issue is often caused by a fault in the wiring, connectors, or components like the reductant injector or pump.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to search for any related codes that could provide more information about the source of the problem. | OBD-II Scanner |
| Measure Voltage in the Circuit | Use a multimeter to measure the voltage in the supply control circuit and compare it with manufacturer specifications to confirm low voltage. | Multimeter |
| Test Components | Test components like the reductant injector or pump using diagnostic tools to ensure they are operating within the correct voltage range. | Multimeter, Diagnostic Tool |
| Inspect Wiring and Connectors | Check the wiring and connectors for signs of damage, corrosion, or disconnection that could cause the low voltage condition. | Flashlight, Multimeter |
| Clear the Code and Test Drive | After performing repairs, clear the fault code using an OBD-II scanner and take the vehicle for a test drive to confirm the issue is resolved. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | Re-scan the vehicle after the test drive to ensure the P2063 code does not return. If it does, further diagnostics may be needed. | OBD-II Scanner |
Free PDF: How to choose OBD2 scanner
I’ve made you a free PDF to choose the OBD2 scanner in 5 minutes.
✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
Just tell me where to send it.
Hi, I am Juraj “Yuri” Lukacko. I got frustrated by unhelpful and scammy mechanics, so I decided to learn everything about car diagnostics myself. I test dozens of new car diagnostic tools every month along with learning new strategies to fix and customize cars. About Juraj Lukacko (Yuri)